How to Choose an Avalanche Airbag Backpack
AVALANCHE AIRBAG BACKPACKS WORK?
Regardless of brand, all avalanche airbags work on the same principle; referred to in scientific circles as the principle of Inverse Segregation. Put simply, this states that when in motion, larger objects will always move to the top. This is also true of an avalanche. By inflating large airbags, avalanche airbag packs significantly increase your volume and help keep you on top of an avalanche rather than getting buried underneath.
This phenomenon is also referred to as the "Brazil Nut Effect" based on the fact that in a container of mixed nuts the largest nuts (the Brazil nuts) will find their way to the top. The same is true for muesli, where the larger bits of fruit and nuts always end up on the top. So next time you're enjoying a bowl of muesli, grab the pack, give it a shake and you can marvel at the wonders of Inverse Segregation in action!
Although the method of inflation and the design of the airbags differ slightly from brand to brand, the mechanisms for inflation share the same general design. The airbag/s is packed into specific compartment/s on a pack and triggered by the wearer pulling a handle which initiates the inflation mechanism. This then kick starts the inflation of the airbag/s with extra air being drawn into the system by the Venturi effect.
CONSIDERATIONS BEFORE BUYING
AN AVALANCHE AIRBAG BACKPACK
Consider what type of skiing/snowboarding you will be doing and then align the capacity of your chosen pack with your intended use. For example heli accessed sessions or freeriding within close proximity to lift accessed terrain requires you to carry significantly less kit than if you were heading out on a full day tour into the backcountry. Below is a rough guide to capacities, this is a guide only as individual requirements/preferences differ:
- Lift served backcountry, heli & cat trips: 15-20L
- Day touring: 20-35L
- Multi day touring: 35L+
Travelling With Your Avalanche Airbag
Although legislation exists allowing you to fly with avalanche airbag packs, different airlines have different rules, and regulations change depending on where you are heading – for example European, American and Canadian regulations all vary.
The availability of support in the form of canister hire, refill and exchange programmes also vary by location, so it's worth checking in advance if you are going to need to access replacement canisters while you are away. For more detailed information, check out the Airbag Travel section below.
Equipment carry options
Different packs will have different options for carrying skis, board, helmet, ice axes and other essential equipment. Your requirements will be led by your intended use as well as personal preferences; make sure the pack you choose has the options that you want.
Size and fit
Your pack needs to fit well and be comfortable to carry. On some models the position of the airbags after inflation is important and so it's vital that you get a pack which fits your torso correctly. If size options are available make sure you check out size guides to get the right fit. Where possible we recommend heading into one of our stores where our staff can help you select the right model.
Traditionally airbags have been inflated by using a canister/cylinder of compressed gas (air or nitrogen). In these systems, the pulling of a trigger handle causes the canister to be pierced and the resulting rush of gas from the canister kick starts the Venturi effect which fills the airbag/s in a matter of seconds.
The 2014/15 season saw the arrival of a new system developed by Black Diamond and Pieps which offers an alternative to the canister systems. Known as JetForce Technology this system uses a battery powered fan as the airbag inflation mechanism.
Mammut Snowpulse Airbag Technology
There are two designs of airbag systems available in Mammut Snowpulse packs: the Protection Airbag System and the Removable Airbag System (R.A.S). The operation of both systems is the same, with a simple and effective mechanical system that utilises a compressed gas canister for activation. In addition both systems are 'removable' meaning that they can be taken out of the backpack. This enables use of the pack by itself for activities not requiring airbag protection, as well as allowing the system to be installed in other compatible packs, giving the user the versatility of having several different capacity packs suited to different trips.
While the operation of both systems is the same, the airbag designs are different:
Protection Airbag System
The Protection Airbag System is the newly developed version of the well-known Snowpulse Lifebag System. The unique shape of the airbag protects the wearer's head, neck and chest area from mechanical injuries and in the event of an avalanche ensures an optimal position by keeping the wearer's head and upper body on the surface.
Removable Airbag System (R.A.S)
This version features a large rectangular shaped airbag which inflates behind the users head. Simple to use, this system ensures a lightweight pack that is very comfortable to wear. The design of the airbag is also favoured by snowboarders due to that fact that it maintains good peripheral vision after deployment; allowing users to activate the airbag if things get sketchy, but still attempt to board out of harm's way.
ABS TwinAirbag System
ABS's TwinAirbag System features two separate airbags which inflate simultaneously, but have separate closure and suction valves. This unique design offers advantages in terms of how the airbags perform when the user is caught in an avalanche; their shape and position increase the chances of staying on the surface of the avalanche and reduces the risk of injury. Two airbags also offer double the safety; if one airbag gets damaged you'll still have the other to help keep you from being buried.
The ABS system uses a compressed gas canister and activation handle with pneumatic charge in it to inflate the airbags. On pulling the handle a pressurised capsule in the handle goes off and it is the explosive pressure that triggers the piercing of the canister. ABS airbag systems are available in their own packs as well as a number of partner packs such as The North Face Patrol 24 ABS pack.
Black Diamond JetForce Technology
JetForce Technology, the result of a multi-year collaboration between Black Diamond and PIEPS, is the first avalanche airbag system to use jet-fan inflation. Rather than relying on compressed gas canisters, the system uses a rechargeable battery to power a fan which starts the Venturi effect that fills the airbag.
By using a rechargeable electronic system, JetForce packs have some key benefits over canister systems. They offer easy air travel, with little to no restrictions on the batteries as they're no different to laptop batteries. The use of a rechargeable battery also enables zero-cost user practice as activating the system doesn't require the purchase of any new components.
The electronic system also allows some clever performance features such as system self-diagnosis and its ability to continue to run the fan after inflation, ensuring that it maintains full volume and enables recovery from any small punctures.
AVALANCHE AIRBAG PACKS
The pressurised canisters used in avalanche airbags are classed as hazardous goods and their transportation by aircraft is subject to restrictions and regulations. In normal circumstances, individuals are not permitted to transport hazardous goods on an aircraft, but a special IATA regulation exists, permitting one canister per person for use with an 'Avalanche Rescue Backpack'.
To fly with your airbag, however, you need to plan ahead. Prior approval is required by the airline and it is recommended that you notify them when booking your flight, or at least 14 days in advance. You will need to contact your airline operator to advise them that you will be flying with an avalanche airbag pack and canister – it is advisable to refer to your pack as an 'Avalanche Rescue Backpack' as this is how it is described in the regulations. You will also need to send the appropriate canister data sheets together with the extract from the IATA Table 2.3A to your airline operator when contacting them.
When flying you will need to make sure the pack is packed in a manner that prevents accidental activation (the canister must not be screwed in and activation handle must be removed/stowed). Include a copy of the canister data sheet and IATA Table with your pack.
Travelling to or from the United States
If you are traveling to or from North America, the US American Transportation Safety Administration (TSA) will not allow your pressurised canister on board. You will either need a canister that can be discharged so that you can fly with it empty or look to hire a canister on your arrival.
For canister based systems you will need to consider how you will manage replacement canisters. Airbag packs use specific canisters and these aren’t interchangeable between brands so it is very important that you know which canisters your system uses and only purchase genuine replacements from an approved dealer.
Once you set off your airbag – either in an avalanche scenario or a practice deployment – you will need to source a replacement canister. Luckily this is normally fairly easy and cheap to do, but it will require some forward planning so that you don’t get stuck without a canister.
Mammut Snowpulse replacement canisters
All Mammut Snowpulse packs from winter 2011/2012 onwards can be used with two different canister types: a non-refillable canister (steel or carbon versions are available) and a larger refillable version.
The version primarily used in Europe is the smaller non-refillable version, which meets IATA regulations to be allowed on-board an aircraft. After deployment this will need to be returned to the manufacturer for refilling. There is an extensive canister exchange programme in place for these so that customers can take their used canister into participating retailers and exchange it for a new one (a service charge will apply).
The larger refillable version is primarily used in the States where flying with the smaller canister is prohibited. This version has a pressure gauge and can be refilled from a compressed air tank – either at an approved retailer or dive shop. This means the canister can be emptied prior to flying and then refilled on arrival, allowing users to meet TSA regulations.
ABS TwinAirbag System replacement canisters
ABS TwinAirbag packs use a compressed gas canister (steel and carbon versions are available) and a specific trigger handle to activate the airbags; both must be replaced after deployment. The canister and handle must be returned to ABS for refilling after use. In order to support customers looking to access replacement canisters and trigger handles ABS has set up an extensive canister exchange programme whereby for a small charge customers can swap their used canister (and trigger handle) for a new unit at participating retailers.
These canisters are approved by the IATA so providing you book in your airbag pack, you should be able to fly with them in Europe. However, for the States you must either fly with an empty canister (and look to exchange at a participating retailer) or fly without and look to rent one on arrival.
Ellis Brigham is affiliated with both the Mammut and ABS canister exchange programmes. For more information, please contact our expert Mail Order team on 0800 035 6483 or via email: firstname.lastname@example.org